Catalytic cracking diesel fuel hydroconversion method

Abstract

The present invention discloses a catalytic cracking diesel fuel hydroconversion method. According to the method, catalytic diesel fuel and hydrogen are mixed and then enter a hydrorefining reactor to carry out a hydrorefining reaction; the hydrorefining reaction effluent directly enters a hydrocracking reactor and then is subjected to a contact reaction with the grading catalyst bed layer inside the hydrocracking reactor, wherein at least two cracking catalyst bed layers are arranged inside the hydrocracking reactor, and the hydrogenation activity of the hydrocracking catalyst presents the decrease tendency according to the reaction material flowing direction; and the hydrocracking reaction effluent is subjected to separation and fractionation to obtain the naphtha and the diesel fuel. With the method of the present invention, the diesel fuel hydrocracking effect can be ensured while the excessive hydrogenation and the secondary cracking of the naphtha can be reduced and the chemical hydrogen consumption can be reduced so as to increase the octane number and the liquid yield of the naphtha.

Description

technical field [0001] The invention relates to a method for hydrogenation treatment of hydrocarbons, in particular to a method for hydrogenation conversion of catalytic cracking diesel oil. Background technique [0002] Since the beginning of the new century, with the increasing awareness of environmental protection, the stricter national environmental protection regulations and the rapid development of the national economy, the demand for clean motor fuels has been increasing all over the world. Catalytic cracking (FCC) technology is one of the main technological means for lightening heavy oil, and it occupies a relatively important position in oil refining enterprises all over the world. The annual processing capacity of catalytic cracking units in my country has exceeded 100 million tons, second only to the United States. In the composition of gasoline and diesel products, catalytic cracking gasoline accounts for about 80%, and catalytic diesel oil accounts for about 30...

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Problems solved by technology

But at present, there are also some problems in the existing technology. The main purpose of high aromatics diesel conversion technology is to convert high aromatics diesel into high octane gasoline components. At the same time, reduce the sulfur content of diesel and improve the cetane number of diesel, gasoline There is a contradiction between the hydrogenation of diesel components and diesel components. When the hydrogenation capacity of the catalyst in the cracking section is too strong, the gasoline components produced by cracking will be excessively hydrogenated, and the octane number of the product will be low. However, when the hydrogenation capacity of the catalyst in the cracking section is insufficient , the quality of diesel products is poor, and at the same time, it will accelerate the carbon deposition rate of the catalyst and affect the long-term operation

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